Floor drain with a hidden thread clamp.

ABSTRACT

A thinset floor drain comprises a floor-mounted flanged pipe piece presenting a hidden thread inside a deep ring-shaped groove formed into the upper surface of the flange, and a second flanged pipe piece with an internal thread. The first piece is mounted pipe down in a perforation in the subfloor of a wet room with screws. The second piece is threaded from above into the hidden thread to form a clamp for a perforated sheet of membrane placed interstitially to the two flanges drawn together by the engagement of the thread mate, to achieve a watertight connection between the drain and the membrane. Because the thread mate sits largely below the subfloor tow which the floor drain is mounted, the upper surface of a grate assembly threaded into the mounted and clamped drain will present a low profile above the surface of the subfloor.

CROSS-REFERENCE TO RELATED APPLICATIONS

No cross reference is made to other applications.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OF DEVELOPMENT

No Federal Government support was received in the development of this Invention.

SEQUENCE LISTING, TABLE, OR COMPUTER PROGRAM LISTING

No sequence listing, table, or computer program is attached or accompanies this Application.

FIELD OF THE INVENTION

The present invention relates generally to wet room drains, and more particularly to tile shower drains that integrate membrane as a means of waterproofing wet room tile floors. A tile shower drain is a device mounted in a tile wet room floor that drains off shower water collecting on the wet room floor, a wet room being a waterproofed bathing room. Waterproofing is effected in a wet room by a system of membranes, mortar, tiles, and spacer material, and more particularly by a membrane. Integration of the membrane into the tiled shower drain refers to the provision of a continuous, waterproof tile surface sloping down to the shower drain, wherein the membrane under the tile is clamped or adhered or both to the drain in such a way that water does not egress to below the membrane and beyond to the fabric of the building. Further, wet room floor drains must not protrude above the level of the tiles surrounding the drain, and therefore must accommodate clamping features below the subfloor.

BACKGROUND OF THE INVENTION

Waterproofing of a wet room is an exercise in preventing the water emanating from a shower or other water supply fittings from entering the fabric of the building and causing damage. The term wet room describes a room where water is supplied into the room using piping for purposes of bathing and exits the building using piping to a plurality of sewerage options. Common waterproofing components of the floor of a membrane to ensure water does not instead drain into the fabric of the building include a drain fitting, membrane, mud or mortar, tiles, tile adhesive, and grouting. A drain fitting comprises a flanged pipe for concentric attachment at the lower, unflanged, end to a drainage pipe attached to a downstream underlying sewer system, with the flange on the upper end of the drain resting on one of a plurality of floor perforations. A membrane is a sheet of waterproof material. Mud refers to a shapeable, self-drying, viscous mortar used to build a sloped base for the application of tiles. Mortar itself is a viscous mixture that holds shape until it dries solid, allowing for the formation of sloped surfaces. Mortar typically is not waterproof, and does not form a barrier to water flow. Tile adhesive adheres the underside of tiles to mud or membrane. Tiles are planar ceramic or plastic polygonal components that play a decorative and hygienic role and help to protect the underlying mud or mortar from impact and water. Grouting or grout fills the spaces between tiles to add to the waterproof nature of the upmost tiled surface. While tiles are often waterproof, grouting is a poor barrier against water flow. A sub-floor refers to the unfinished lowermost flooring underlying tile systems. Wet room drains include but are not restricted to shower drains located in showering spaces, other examples being wet room drains to receive bath tailpieces, where the tailpiece is a vertically suspended brass tube emanating from the bath waste fitting, or toilet horns, where a toilet horn is a vertically suspended drain pipe bottommost to the toilet body, and floor drains, which simply drain water from the floor. With the rise of a diversity of water supply fittings in the wet room, the wet room floor drain and the wet room shower drain become one and the same fitting.

In a wet room waterproofing system, the floor drain as installed in the tiled wet room performs two drainage functions, one, grate drainage, and, two, weeping drainage. Grate drainage is achieved through the provision of perforation in the uppermost portion of the drain such that water free-flowing atop the tiles flows down the slopes provided in the tile surface to drain through the uppermost perforation of the drain, through the drain body, and through the building drainage system to the primary sanitary drain serving that building. Said upper perforation of the drain is usually protected by a grate. A drain grate is defined as a generally planar thin fitting that is attached atop the drain perforation. A drain bearing a grate allows the majority of influent water to drain through the grate and downstream to the sewer. A second drainage function is termed weeping. Weeping refers to the relatively smaller flow of water that passes through small cracks in the grout, and collects at the first waterproof boundary encountered, the membrane. Tiles and grout form an imperfect waterproof barrier in any tiled system. Water draining through imperfections in the grout and tile floor is unavoidable. A floor drain for tiled wet rooms must provide a secondary drainage feature that is seamlessly connected to the first impervious layer, the membrane, to capture and drain weeping water beneath the tiles. This will permit the water that has passed through the tile floor to drain to the sewer.

Floor drain design varies with the system of waterproof wet room construction used for a tiled floor. Two construction systems using components including membranes, mortar, and tiles have evolved: traditional and thinset. Traditional tiled wet room waterproofing systems comprise a waterproof membrane sheet placed directly over the subfloor and linked to a drain mounted to the floor by fasteners. The means by which a membrane is fastened to the floor-mounted portion of the drain includes chemical adherence, or by clamping rings that sandwich the membrane and are fastened by bolts perforating the membrane when passing through the membrane to be tightened in bolt mounts provided on the floor-mounted portion of the floor drain. In the traditional method, mud is then shaped over this membrane to provide slope in the floor promoting the drainage of water toward a centrally placed floor drain. Tile adhesive is applied to the dried mud. Tile is then placed on the adhesive and sealed with grout. This traditional waterproofing system for tiled wet rooms is problematic owing to the lack of bonding between the mud and the subfloor. Cracks developing in the shifting dried mud mass lead to shifting of the overlying tiles leading to subsequent breakage of grouting between the tiles. Water weeping through the tiles accumulates in the mortar above the membrane. Although weeping features are provided in the floor mount of such drains, said weeping features are commonly blocked by the shifted and wetted mud.

In contrast, the thinset waterproofing system employs a range of mud formulations ranging from self-drying liquid mud to stiff shapeable mud, or hard foam, or both, to build a largely waterproof mass that both provides for sloping to a drain mounted directly on the subfloor, this mud bonding directly to the subfloor to control shifting. To this slope an impervious membrane layer is applied or formed chemically. A thin layer of tile adhesive, thinset, is applied to the top of the resulting layered structure, and tiles and grout applied. Water directly flows over the tiles and grout to the grate to drain. Any water weeping through the tile grout layer immediately encounters the membrane overlaying the sloped mud, causing the weeping water to weep toward the drain and drain via weeping features decorating the upper flange of the floor-mounted drain. To minimize the volume of mud applied, the thinset floor drain is mounted as closely as possible to the subfloor and the tiles surrounding the drain are glue just above the membrane, requiring the bulk of the thinset floor drain structure to be below the subfloor.

This Application describes a novel means of clamping the membrane in the thinset tiling method. The clamp consists of the vertical mating of two clamping pieces. The upper piece is a flanged pipe with internal threading on the pipe. The second, lower, piece is a subfloor-mounted, flanged pipe that penetrates the subfloor and bears a connection hub at the lowermost, non-flanged, end of the pipe. A thread is formed in the inner wall of a void perforating the upper, flanged, surface of the floor-mounted flanged pipe, said void being ring-shaped in horizontal cross section but not penetrating the pipe wall at the lowermost hub end. This ring void is concentric with an inner and complete circular perforation of the drain. The internal thread of the uppermost flanged pipe engages the thread formed into the inner wall of the ring void formed into the lowermost, mounted, flanged piece. When the two flanges meet, they can clamp an interstitial sheet of membrane perforated by an appropriately sized hole.

Culwell (U.S. Pat. No. 8,955,172, Feb. 17, 2015) uses fasteners to fasten the flange of a toilet attachment assembly to the subfloor, overlays with membrane, and clamps the membrane with a clamping ring onto an externally threaded pipe presenting upward from the flange surface of the mounted piece. An upward externally threaded pipe may be suitable for toilets but is not useable in floor drains, which have to present as minimal a height as possible above the subfloor. In contrast, when a grate subassembly is fitted to the mounted membrane clamp as described in the Invention in this Application, the grate will not protrude beyond the height of the tile surrounding the drain, owing to the provision of a hidden thread mate below the surface of the subfloor, again as described in this Application.

Schlueter (U.S. Pat. No. 9,567,738, Feb. 14, 2017) uses fasteners to secure two clamping flanges above and below a membrane being joined to a linear drain. Any perforation of a membrane peripheral to the central drain perforation presents a risk of leakage. In contrast, the Invention presented in this Application avoids any peripheral perforation of the clamped membrane.

Accordingly, the mounted membrane clamp described in this Invention addresses shortcomings in existing, recent, membrane clamp patents through the provision of a hidden threadmate extending below the subfloor.

SUMMARY OF THE INVENTION

A floor drain with a hidden thread clamp thinset membrane clamp as described in this Application consists of two pieces, a flanged pipe that is fastened to the subfloor such that the pipe penetrates downwardly a hole in the subfloor and the flange presents upward, with the flange bearing two perforations: a central hole completely perforating the flanged pipe surrounded by a ring shaped groove not completely penetrating to the bottom. Inside the ring shaped groove a thread decorates the innermost wall. An upper flanged pipe decorated with a thread on the interior of the pipe engages the mounted hidden thread. The two flanges are drawn together and form a clamp for an interstitially placed, perforated, membrane.

The thinset drain described in this Application provides both drainage functions; that is, the drain comprises a perforation grate that collects the majority of drainage water as well secondary weeping drainage channels that drain water weeping along and above the impervious membrane directly below the tile surface into the same central drain perforation, without need for gravel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric exploded view of the thinset drain assembly decribed in this Application, including a piece of perforated membrane sheet and a grate subassembly.

FIG. 2 is an exploded view of the thinset drain showing the two flanges that will clamp to the membrane when the threadmate is engaged.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1, the thinset drain described in this Application is shown. A flanged, internally threaded pipe 8 is threaded, with an optional key 6 fitting weeping features in the upper surface of the flange 2, into a flanged pipe 10 itself mountable onto a subfloor by fasteners including but not restricted to screws passing through flange perforations 12 into a subfloor. When the two threaded pieces are engaged and tightened, an interstitial membrane sheet 3 adorned with a central drainage perforation 9 is clamped firmly. Adhesives may be applied to the top and bottom of the membrane 3 for secondary sealing. To finish the drain, one of a plurality of subassemblies can be fitted to the upper perforation. In this diagram a tile 5 rests in a tile tray 4 threading to the upper flanged pipe 8 clamping piece. A hub 7 engages a standard sized pipe for attachment to downstream plumbing including but not restricted to a trap.

In FIG. 2, the mounted flanged pipe 10 that appears lowermost in the figure is threaded with a hidden thread to receive an internally threaded, flanged, pipe 2 to clamp an interstitially placed membrane sheet 3. An optional key 6 may be used for tightening the clamp. The central perforation 11 of the upper clamping piece can accept any of a plurality of threaded subassemblies including the tile tray 4 as illustrated. 

1. A membrane clamp consisting of two pieces, a flanged pipe piece that is fastened to the subfloor such that the pipe downwardly penetrates a hole in the subfloor and the flange presents upward, and an upper flanged pipe piece, wherein: the engagement of a thread internal to the pipe feature of the upper piece into a hidden thread formed on the inner side of a deep circular groove concentric to the central drainage perforation in the upper surface of the flange of the lower mounted piece, serves to clamp an interstitial membrane for the waterproof attachment of the drain to the membrane necessary for a watertight wet room floor.
 2. A floor drain equipped with a membrane clamp as claimed in claim 1 wherein: a grate subassembly can be threaded to an appropriate depth into the thread internal to the pipe of the upper flanged pipe to provide a grate surface contiguous with the upper surface of the tiles, owing to all threadmates being located substantially below the surface of the subfloor.
 3. A floor drain equipped with a membrane clamp as claimed in claim 1 wherein: weeping features in the upper flange of the upper flanged pipe piece allow for weeping drainage of wet room water draining through tile grout and along the membrane surface sloped toward the drain into the central drainage perforation, avoiding the need for provision of gravel for weeping. 